A CONSTANT DISCHARGE DEVICE FOR AQUIFER TESTS ON LARGE‐DIAMETER WELLS

. The discharge in pumping tests conducted on large-diameter wells declines with the fall of water level. This violates the basic requirement of pumping tests that the discharge should remain constant. A simple device to keep the discharge constant has therefore been developed. This device is also useful in keeping the discharge much lower than the rated capacity of the farmer's pump, and thus in increasing the total test period. The discharge from the farmer's pump is released in a barrel having a V-notch at the top and an arrangement for returning a part of the discharge to the well. The return flow is gradually reduced through a control valve, and thus the net outflow is kept constant. This device has been used for conducting pumping tests on several dug wells.